1. Field of the Invention
The invention relates to a rotary actuator, having a cylinder and motor shaft, as well as end caps which define a work chamber. A number of ribs on the inside surface of the cylinder and an equal number of vanes on the motor shaft divide the working area into work chambers which are alternately supplied with hydraulic medium. In addition, seal units can be provided inside grooves in the ribs and vanes to hydraulically separate the work chambers from one another.
2. Background Information
Rotary actuators are known on which a manufacturing problem occurs in manufacturing the grooves for the seal units in the ribs and vanes. The seal unite used have a width/weight ratio which is unfavorable for machining the inside of the cylinder. Previously, the grooves could only be manufactured to within the required tolerances by means of very costly and complex manufacturing processes, such as spark erosion or slotting. The associated manufacturing expense is unacceptable for large-seals series production. More economical manufacturing processes, such as broaching with a broaching tool, have failed in the past because the broaching tools broke very quickly due to their small cross-section.